ations. I have no space to give even an
abstract of his conclusions. I can only refer to his proof of the fact,
that a single cell may send its processes into several different bundles
of nerve-roots, and to his demonstration of the curved ascending and
descending fibres from the posterior nerveroots, to reach what he has
called the longitudinal columns of the cornea. I must also mention Dr.
Dean's exquisite microscopic photographs from sections of the medulla
oblongata, which appear to me to promise a new development, if not a new
epoch, in anatomical art.

It having been settled that the nerve-tubes can very commonly be traced
directly to the nerve-cells, the object of all the observers in this
department of anatomy is to follow these tubes to their origin. We have
an infinite snarl of telegraph wires, and we may be reasonably sure,
that, if we can follow them up, we shall find each of them ends in a
battery somewhere. One of the most interesting problems is to find the
ganglionic origin of the great nerves of the medulla oblongata, and this
is the end to which, by the aid of the most delicate sections, colored so
as to bring out their details, mounted so as to be imperishable,
magnified by the best instruments, and now self-recorded in the light of
the truth-telling sunbeam, our fellow-student is making a steady progress
in a labor which I think bids fair to rank with the most valuable
contributions to histology that we have had from this side of the
Atlantic.

It is interesting to see how old questions are incidentally settled in
the course of these new investigations. Thus, Mr. Clarke's dissections,
confirmed by preparations of Mr. Dean's which I have myself examined,
placed the fact of the decussation of the pyramids--denied by Haller, by
Morgagni, and even by Stilling--beyond doubt. So the spinal canal, the
existence of which, at least in the adult, has been so often disputed,
appears as a coarse and unequivocal anatomical fact in many of the
preparations referred to.

While these studies of the structure of the cord have been going on, the
ingenious and indefatigable Brown-Sequard has been investigating the
functions of its different parts with equal diligence. The microscopic
anatomists had shown that the ganglionic corpuscles of the gray matter of
the cord are connected with each other by their processes, as well as
with the nerve-roots. M. Brown-Sequard has proved by numerous
experiments that the gray subs